package com.itheima.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.common.BaseContext;
import com.itheima.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

//登录拦截过滤器
@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {
    //路径匹配器,支持通配符比较
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        //1.获取本次请求的URI
        String requestURI = request.getRequestURI();
        log.info("拦截到请求:{}",requestURI);

        //定义不需要处理的请求路径
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "front/**"
        };
        //2.判断本次请求是否需要处理
        boolean check = check(urls, requestURI);
        //3.如果不需要处理,则直接放行
        if (check){
            filterChain.doFilter(request,response);
            return;
        }
        //4.判断登录状态,如果已登录,则直接放行
        if (request.getSession().getAttribute("employee") != null){
            BaseContext.setCurrentId((Long) request.getSession().getAttribute("employee"));
            filterChain.doFilter(request,response);
            return;
        }
        //5.如果未登录则返回未登录结果,通过输出流方式向客户端响应数据
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));

    }

    //路径匹配,检查本次请求是否需要放行
    public Boolean check(String[] urls, String requestURI) {
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match) {
                return true;
            }
        }
        return false;
    }
}
